Separatists in an English-speaking part of Cameroon have kidnapped a former top judge, a source said on Monday, marking a fresh escalation in the troubled region.Martin Mbeng had retired last year as vice president of the court of appeal in the Southwest Region, which with the neighbouring Northwest Region is in the grip of violent unrest."Mbeng is in the hands of the supporters of secession," lawyer Agbor Nkongho, a friend of the judge and head of a campaign group called the Centre for Human Rights and Democracy in Africa, told AFP.He was abducted on Sunday morning, Nkongho said, confirming information on social media."We condemned this act and asked for him to be released, especially as Mr Mbeng does not engage in any political activity and he is not a supporter of the government," he said.There was no claim for the kidnapping a day later, and the authorities have made no reference to it.Cameroon's Northwest and Southwest Regions are home to most of the country's anglophones - a minority of about 20% in the predominantly French-speaking country of 23.4 million.Resentment among anglophones has steadily built over the years, fuelled by the perception that they suffer discrimination at the hands of the francophone majority.Matters came to a head last year when President Paul Biya rejected demands for greater autonomy, prompting a shift towards radicalism that culminated in the declaration of an independent state that was met by a crackdown.Since then, scores of civilians and members of the security forces have been killed in attacks on both sides, and tens of thousands of civilians have fled to neighbouring Nigeria.Kidnapping has swiftly become a weapon of the separatists.KEEP UPDATED on the latest news from around the continent by subscribing to our FREE newsletter, Hello Africa.FOLLOW News24 Africa on Twitter and Facebook. A deputy prefect and a civil servant were abducted in February in the Northwest Region. Last Wednesday, the government said 12 European tourists were taken hostage "by a band of armed terrorists" - the usual term for separatists - while on a sightseeing tour in the Southwest Region before being rescued by troops.Separately, six municipal councillors in the Northwest Region were released in a military operation, the authorities said.The anglophone question in Cameroon is a legacy of the colonial period in Africa.France and Britain divided up the former German colony under League of Nations mandates after World War I.A year after the French-ruled territory became independent in 1961, the southern part of British Cameroons was integrated into a federal system. Federalism was scrapped 11 years later for a "united republic".